The realization space is
  [1   1   0            x3 - 1   0   1   1             0                                x1*x3 - x1 - x2*x3 + x2 - x3 + 1            x1 - x2 - 1    1]
  [0   1   1   x1*x3 - x2 - x3   0   0   1   x1 - x2 - 1   x1^2*x3 - x1*x2*x3 - x1*x2 - 2*x1*x3 + x2^2 + x2*x3 + x2 + x3      x1^2 - x1*x2 - x1   x2]
  [0   0   0                 0   1   1   1       -x3 + 1                       -x1*x3^2 + 2*x1*x3 - x1 + x3^2 - 2*x3 + 1   -x1*x3 + x1 + x3 - 1   x3]
in the multivariate polynomial ring in 3 variables over ZZ
within the vanishing set of the ideal
Ideal with 3 generators
avoiding the zero loci of the polynomials
RingElem[x1^2*x3 - x1*x2 - x1*x3 - x2*x3 + x2, x1 - 1, x1*x3 - x2 - 2*x3 + 1, 2*x1*x3 - x1 - x2*x3 - 2*x3 + 1, x3, x1 - x2, x1^2*x3 - x1^2 + x1*x2 - x1*x3 + x1 - x2^2 - x2*x3, x1^2*x3 - x1^2 + x1*x2 - 3*x1*x3 + 2*x1 - x2^2 + 2*x3 - 1, x2, x1 - x2 - x3, x1^2*x3^2 - 3*x1*x2*x3 + x1*x2 - 4*x1*x3^2 + 3*x1*x3 - x1 + x2^2*x3 + x2*x3^2 + 2*x2*x3 - x2 + 3*x3^2 - 3*x3 + 1, x3 - 1, x1 - x2 - 1, x1*x3 - x2 - x3, x1^2*x3 - x1*x2 - 4*x1*x3 + x1 + x2*x3 + x2 + 3*x3 - 1, x1 - 2, x2 - x3, x2 - 1, x2 + x3 - 1, x1^2 - x1*x2 + x1*x3 - 2*x1 - x3 + 1, x1^2*x3^2 - x1^2*x3 + x1^2 - x1*x2*x3 - x1*x2 - 3*x1*x3^2 + 3*x1*x3 - 2*x1 + x2^2 + 2*x2*x3 + 2*x3^2 - 2*x3 + 1, x1, x1^2*x3^2 - x1^2*x3 + x1^2 - x1*x2*x3 - x1*x2 - 2*x1*x3^2 + x1*x3 - x1 + x2^2 + 2*x2*x3 + x3^2, x1^2*x3 - x1*x2*x3 - x1*x2 + x1*x3^2 - 4*x1*x3 + x1 + x2^2 + x2*x3 + x2 - x3^2 + 3*x3 - 1, x1 - x2 + x3 - 2]